and figured why not, cheap enough and I wasn't expecting much in terms of quality. They arrived and noticed they were short. When I put them in i couldn't focus because the stage wouldn't rise up enough. Went back to the ad and noticed the 185.

I'm assuming 160 is what I should get. My mistake.

Anyway I searched for a microscope that uses 185 standard out of curiosity. Can't find any.

Hi, fibreoptix, I find it odd that these new and unbranded chineese objectives do not list their: 'tube length' as a spec!? The sellers chart of specs seem quite complete otherwise...hmmm.

Your clinical workhorse stand ( many of these Nikon Labophots are still in active duty in clinical labs) is a DIN standard err 45mm length objectives..with a crucial spec of: 160mm tube length.

I have a collection of three LOMO apochromatic objectives that I bought due the great price on eBay ( thanks Vlad, Chicago,US seller)...I 'pounced' because my brain homed in on their spec of: 160 tube length...sigh, they are RMS standard: about???34mm?? length objectives...thus my Nikon Labophot can't 'focus down' to function with these objectives. Older really vintage microscope do 'focus down' enough for the LOMO 'shorty objectives'. Perhaps hang on to your set of new/unbranded objectives for when you aquire a vintage stand?

It's a great question...what do they mean by: "185" objectives?! Again I'l tell you, fibreoptix, I have a large collection of Nikon objectives and occulars I can sell low cost if you are interested. Just pm me.

I'm glad you are starting with a Labophot...get a trinoc head as soon as you can...and 'trick it out' with Nikon optics rather than 'mix and match' brand optics...but remember it's a 160 tube length spec, and Din: 45 mm objective spec. Charlie Guevara finger lakes/US

Hi, fibreoptix, I find it odd that these new and unbranded chineese objectives do not list their: 'tube length' as a spec!? : 160 tube length...sigh, they are RMS standard: about???34mm?? length Charlie Guevara finger lakes/US

Charlie G. It is not unusual for student grade optics to be unmarked as to the total optical path length( specimen to top of the eyepiece tube). Your Nikon Labophot isn't marked , either. It is in fact 160 + 45= 205mm. 185mm was in some ways a student microscope standard, although many objectives designed for a 185mm system had threads, other than R.M.S. The notice by the seller of 185, was enough to warn a knowledgeable buyer that these objectives would be short: 25mm parfocal, by deduction.

There is NO R.M.S. standard for objective length, only for the standardized R.M.S. thread that is most commonly used on microscopes. The mechanical tube length standard is D.I.N. 58887, by which Deutsches Institut für Normung,, established that the distance from the objective shoulder to the intermediary image should be 150mm and that the intermediary image should be 10mm below the top of the eyepiece tube, totalling 160mm. The length of the objective is not included in this standard. Various systems have existed based in this standard, as well as deviations from this standard; most notably that of Leitz and their cooperative companies( Seibert, the main one), and the early Japanese both of which used a 170mm tube. If the mechanical tube length is 160mm, then the objective parfocal length needs to be added to that, in order to find the total length. Lomo would be 193mm, AO 194, Baker( early) 194, J.I.S. based on a 170mm tube length is 206, Leitz 170mm system was 207mm; the 160mm system was 205mm, Bausch & Lomb 196.7mm, Reichert 197mm, PZO 205mm, Vickers 205mm, most Chinese 205mm. Zeiss for many years was non-conformist as well, with a total length made up of 147mm( instead of 150), 13mm( instead of 10) and 33mm for a total of 193mm. The more modern Zeiss are 205mm.

There is another D.I.N. standard associated with the 45mm parfocal distance utilized concurrently by many manufacturers and the tube lengths associated with infinity microscopes are a whole other thing altogether.

Hi, fibreoptix, I find it odd that these new and unbranded chineese objectives do not list their: 'tube length' as a spec!? The sellers chart of specs seem quite complete otherwise...hmmm.

Your clinical workhorse stand ( many of these Nikon Labophots are still in active duty in clinical labs) is a DIN standard err 45mm length objectives..with a crucial spec of: 160mm tube length.

I have a collection of three LOMO apochromatic objectives that I bought due the great price on eBay ( thanks Vlad, Chicago,US seller)...I 'pounced' because my brain homed in on their spec of: 160 tube length...sigh, they are RMS standard: about???34mm?? length objectives...thus my Nikon Labophot can't 'focus down' to function with these objectives. Older really vintage microscope do 'focus down' enough for the LOMO 'shorty objectives'. Perhaps hang on to your set of new/unbranded objectives for when you aquire a vintage stand?

It's a great question...what do they mean by: "185" objectives?! Again I'l tell you, fibreoptix, I have a large collection of Nikon objectives and occulars I can sell low cost if you are interested. Just pm me.

I'm glad you are starting with a Labophot...get a trinoc head as soon as you can...and 'trick it out' with Nikon optics rather than 'mix and match' brand optics...but remember it's a 160 tube length spec, and Din: 45 mm objective spec. Charlie Guevara finger lakes/US

IF YOU LOOK AT THE OTHER PHOTOS YOU WILL SEE THEY ARE MARKED "160"......

In this case, the objectives are 35mm parfocal( the oil immersion objective would be around 34.5mm +- long from shoulder to tip), so the total length of the system is 195mm. These probably conform to some standard used in China, prior to their almost wholesale adoption of the 45mm D.I.N. standard. Oddly, they didn't just copy over a system from Japan (J.I.S.), originally, because both the objective length; 35mm instead of 36mm , and the tube length are different; 160mm instead of 170mm, yielding very different total lengths of 195mm ,compared to 206mm. It is somewhat puzzling that the J.I.S. standard, used the same tube length as Leitz. One possibility is that in the early days of the development of the Japanese microscope industry, the key player, that eventually morphed into Olympus, Tiyoda and Shimadzu, probably used optics supplied by E. Leitz, subsequently, copying them almost to a T. I have read that the Japanese made ones, used Leitz lenses. The tube was 170mm for sure. Why would they then adopt a 36mm parfocal length, rather than a 37mm parfocal length, for the J.I.S. standard? Well, maybe they measured wrong, or maybe they were influenced by the considerable presence of instruments with other parfocal lengths invading occupied Japan, after the war.

Objectives are a pain when mix n matching, B&L brass, very short, lomo 33, Jena 35, Beck and Wild.. 38? DIN 45. All 160 and all different. I had to mod my Zeiss to work with them all. Luckily the worst mismatch I made was a Leitz 170. Many Lomo's are 190.

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